Metallic stairway



July 10, 1928. 1,676,317

G. L. BENNETT METALLIC STAIRWAY Filed Feb. l, 1926 M INVENTOR Patented July 19, 1923.

GEORGE L. iannivnrnor CLEVELAND; omo.A f

METALLIC scriiinwiiv.

`Application led `'.Eebruary Myinvention relates to metallic stairways,

and more particularly to a stairway construction of which the vmajor .portionthereof is formed of `sheet metal. n A `In addition. to a desirable iireproof property of a stairway embodying my invention', the structure of said stairway isfsuch as to permit the utilizationA therein of standardl ized parts, the dimensions of which partswill be so closely uniform in every respect as to permit arapid and accurate assembly of the stairway structure without the neces-y sityV for any modification of thesev parts in.

order to ensure the accurate fitting of one*A y with relation to another. Hence the parts entering into the stairway may be conven-V iently shipped and delivered at a .building under construction, in convenient knockdo'wn form with the assurance that as'tairway yor stairways may be erected, without requiring machine work in the alterationof parts, or nicety in the selectionand fittingl of parts. Skilled labor is notrequired in the erection of stairways embodying 'my invention, and the weight'of the variousparts.

A entering into a stairway, is sufliciently light V ing into the stairway.

topmake the convenient Vhandling of these parts possible, thus effecting a material saving in the cost of installation, as well as in` the cost of productionofthe parts enter- A stairway embodying my'invention in-y cludestherein a 4sequence of metallic step, units each comprising in a unitary7 ,struct-ure a tread section and a riser section, the tread` section of one step havingy formedtherein a channel adapted to receive the riser of the unit below. `Each tread unit is supported from the stringers in a manner to hold each unit in relation to said -stringers andthe ,tread section of oneunit in its position with relation to the riser of the adjacent* unit. y -Each tread section isprovided with a -nosing adapted t0- retain av non-slip VVcomposi-v tion tread or other wear surface for the tread, the riser of thisunit beingprovided' with a detachable cove for engaging` the wear surface adjacent the riserv and .at the.

same time avoiding .thepresence oty a sharp Vangle in which unsanitary matter will ac- ,1 cumulate. Y

The various step'units are so secured to the stringers as to be supported therefrom Without resting upon stepped cutouts in the stringers, thus permitting these stringersto J serve a's'finop boards at the 'sides vof these i, 192e.. seriai No', 85,105.

units, Whilelat the same time permitting the stringers to be drawn tightly against 'the 'l side edges k.of the severalvst'ep units. The

kmanner of securing y the "step units tothe stringers is suclias to permit their rapid and accurate assembly in the stairway structure while ensuring the transmissiony of all loads Vupon the treads to the stringers and avoid- 4 ing any materiallooseningor racking ofthe stairway structure 'from long continued use,

while permitting the parts lto. be readily tightened in the eventthat any` such'loosa ness should develop.

.Thev invention consists primarily in a inetallic stairwayl embodying therein metallic` stringers, asequence of step units, each unit j being of'sheet metal so formed asKL to include a tread section and a" Vrisersection integral therewith, each tread section having a down"-y ward-ly presented channel la'daptedto span I the edge of the riser section of an adjoining unit, means adapted to receive a bolt,lcarrie`d by and located inwardly of said stringere'.

and upon the lower face of the tread' section ofeacli unit respectively, V, and bolts engaging said means respectively, whereby said` step units are supported from said"stringers,j

and said stringers and said units may be `,drawn tightlytogether; and.r in such other iiovel features 'of construction andfcombination of parts as are hereinafter set' forth and n described, and more particularly'pointed outl v in the claimsfhereto appended. Referring' toV the drawings,

Fig. l is a vertical section throughy por; tion ofa stairway embodying my invention; ,Fig Q'is a front view thereof withfportions of one' of the risers brokenaway,` Fig. V3 is a detail enlarged view showing the construction by which the step units are connected with the stringers;` and A.

Fig. 4 is an end view of the lconstruction` shown in .Fig.v`3. v '4 p 'n I 'Like letters refer to like parts throughout the several views., f In tlieembodimentof the invention shown in 4th@ drawings, the twostringei's arefinf" dicated at a and b, these striiigei'slbeing right and left, but otherwise one a counterpart ofthe other. The manner yof mounting these stringers in'relatioiito a building structure is immaterial to the invention.

'ies' Each of thesefstringers isma'de of heavy sheet metal stock, the outer face of each beiio v `ing substantially flat so vthat it may be vsnugly fitted to the wall of the building.` The upper and lower edges thereof:J when in p0- sition, yareparallel with each other, these stringers being` provided with no steppedportions upon the upperiacelthereot; teireV ceive the treads and risers.

Supported from, and between, stringers, is a plurality of step unitslso constructed as to co-operate with each other and with the stringers in rigidly securingpthem in relation to said stringere and to each other. y

Each oi-these step units is a replica o'l every other, and a detailed description ot but one of them is therefore nicessary.Y

Each of the step units is composed ot' sheet, metal stock formed or bent at a 900 angle to afford a tread section c, and a riser section d, these part-s being integrally formed in order to. simplify and chea-pen the pro- Y duction of the unit. The width" ofthe unit f may be varied according to thewidth ot the stairway, and the depth of the tread section, and 'the height ot the riser section, may also be varied according to the requirementsVV or'` the stairway construction, rlhe width of each step unit is such as to bring the ends thereof, wlienvasseinbling the stairway into a close slidingtitwith thestringers a andb, the vertical stresses upon each-unit being transmittedte these stringersi through co-operatmg meansformedupon or carried by the stringers, and formed uponor can 4riedby thet under face ofthe tread section et each unit, these members beingadapted.

respectively to receivea bolt, which in4 addition'v to, receiving and'4 transmitting such stresses to the stringere, are also utilized to draw the st ringers tightly against-*the ends of the tread andvrisersections ot'reaen" step unit. Rigidityis imparted to each step unit by the riser section of, that unit, and of the step unitvbelow, andbya'chan- 'nel `memberfc o7op erating Withnthe friser secupon the stringer with which the bolt co.

operates, said bolt being so formed as to support the tread section of the step unit.

In the drawings the, sockets upon the stringere, ordinarily ,two of such, rectilineally arranged being Jformed nponeach Stringer' in relation to each step unit, areindicatedv at e as to the stringerc and f as tothe stringer b. ets e are indicated at,v g and those adjacent the sockets f at L. rlhe bolt passing through these-` The stirrups adjacent vthe `soekv the stirrups g and engaging the sockets e are indicatedat and those passingthrougn the stir-rups Ly and engaging the sockets areindicatedlat rllhe stirrups Lg/-/t are secured to the under side of the tread section 0 of. eachlunit in any desired manner, prelerably by spot, or other, welding methods which wilt malte these stirrups practically an integral part of the step unit.

Each socket e and f'opens upwardly thereof as at 7c andis provided with an opening below the top thereof so as to torni a bar.-y rier or abutment 'nt which by' engagement with a specially 'formedhead a uponV each bolt i or j Will resist any lifting` stresses upon the step unit, and supportY the tread section of the step unit Withwhich ysaidb'olts co-operate.

Each of said bolts, in lieu-ofthe ordinaryhead, hasa hooked end a" adaptedto enter the opening m otits co-operating` socket/.eer

7", and a shouldered rest a2 adapted to bear Vagainst and support the tread section c.'

The screw-threaded,end ot the bolt has mounted thereon a nut 0 adapted to bear against an end of the stirrup i'or the pui# pose of taking up any looseness between an.

end of the step unit and the y adjacent Stringer, and locking the step junit with relation to the stringer.

Each tread section c, to permit ready ac-v cess to the, nut o upon the screw-threaded end of each bolt has an opening; 0 termed therethrough adjacent the'point of attachment of the stirruprg or 71, thereto, thus per mitting` the tighteningof 'the parts entering into the stairway structure, from the steps.:

themselves.

Each tread section c is provided with aj nosing p adapted to receive and'retainv a wear tread g' upon said'tread section, this wear tread preterablybeing otanti-friction or ynon-slip material. Adjacent said n osing",

the inetaljis so formed as to presenta down;

wardly opening channel p 'extendingtor the ull` Width oi" the treadV section and so located as to receive the top edge ot the riser This channelp will `Y compensate 'for any slight variance in the f height of therisers of ditferent'step units and will stiften said riser, and the tread carrying it, thus adding tothe rigidity et Preferably the nosing of the step unitbelow.

the entire structure.

piece and the channel are formed from a.

separate strip of sheetmetal and secured -in any desired manner, as by spot, or other, welding methods, to a-downturnedfr flange c upon the treadsection of the uniticariy-V ing the nosing. By so constructing; the nosing` and the tread section, the production et the step unit is simplied'trom theimanuacturing standpoint, and,- yet tlie-'nosingv and channel, to ally intents and purposes,f

forms an integral part of the stepunit.

To permit the convenient 1 mounting and;

l the'varius stepA a-ndntheI bolts theirunassembled relation so that'vtheyfmay be. assembled by :the workmen on thef obi` In Y so VLassembling a stairway embodying thel in-,` Ventio'n, the stringersa .andrfb are lfirst ,set in the` desiredvrelation, with the y.sockets ,e andf, presented towardgeach other.: "The, bolts are. 7,then e ifittedf in. thej stirrups Y vadrjacentv the `opposite 'endS O,v the V,varioifis step4k unitsfthe bearing -portion n2- ofl these. rbolts preventing --.rotative movement. thereofffin. relationv tofth'e stirrup g* or h.. fyWhen 'the' 'yreplaceinentof the wear treadfg 'withrelationste the tread'section c`,`I -p1'oyide each risenwithf a -r'emovablefmetal cove-piece r.

which in addition toholding the'wear tread in'jrelation to jthe; nosing rwil'l .also serve togproduee a curved cove atlthe junctio'nroi' tlrisf'wear plate qwvith theriser 'section-Zr stresses of use .to `whichthe: stairwayI issulo-y jl jeeted, notwithstanding thelight weight grof Y tlhe'st'ructure; whilevfat the:A Same. time? not beingfsubjeet to likelihoodof. fracture-,in

' the event. rotal :sudden: lsharpzimpactfof any objectgthe'rewith.

i v'In' the eretion; of .a stairway*l structure emvbodying Athe invention,L it vmay be necessary! to.v provide aflat riserfplate tico-operating withv the channel p of thelowermostfstep unitgrwhic'h riseivplate t may be secured-1n relationto the lower landing ofi-the' stair` way in any desired manner.v The finishofV the. upper l'landing'i'or .the stairway at lthe edge'.thereof` adjacent-the riser` d of the;

uppermost step unit will be such as to protectthe fupper edge oftsaidriservsection.

'.VVh-ile,r if `desired thefstair-wayv lnayfbe assembled-inthe shop and shippedto the sitev4 of.: its installation;itwill ordinarily -zbe` found iniore convenient toship the stringe/rs',

boltsrrare so positionedr'rthe' lowerrnost,V step unitlris Inerelyd'ropped :in theqproper 'position between 1 thest ringers, the' hooked ends; :i afyof lsaid bolts' or jfpassingthrough the open-tope cifof the socket ,e or -f'cwith'-whieh the boltis toco-,ope'rate until the hoolrnnf; f is ,perniitted toenter -the opening forming 'the a-buflnente i Them# 0 'isi then tight:` "l cned, drawn'gl-vsaidf heekedl @edv af belen the abutment mand; et theasamtm@ ,draw-1? gagingE relatjonfwithfthe treadand riser see-,fl

` uniti"being, V pa cedure isjrepeated with the succeeding step'sl upwardly',.ther downwardly )presentedchan-y Y if' section cl oftthe unitzbelow.`

- It is preferab'leinot to draw 'ther too tightly until all ofthe step units hayefbeenf mounted with relationwto and -between the; stringers, the openings o being :provided to permit the `insertion of af-spanner wrench for the final tightening foi' .the various nu'tsV permit them t'o-be flexedrsufiiciently to draw.

AThe lightfmetalstock ofthe stringere will Y i' them" tight against the ends of the step i' units as describedypit. `.being `possib'le,` how,- eyer, jto make these stepunits oit-sufficient, uniformity as-to width to reduce the amount .of clearance between the` ends` of. each step unit l and the adjacent risers, to requirefa movement vofthe stringers so small las Znot to be appreciable. fIn Ifact lthe clearance allowed between the. risers I andfea'ch step unit is merely sufficient to permit' the units to be readily placed jinposition. AThe Weark treads '51g after lthe `stairwaystructure has been properly f tightened throughout, are pol'y sitioned. upon the tread-sections dof the,

several; rstepi units by means otlie; spring ee j" coves r, thus ,avoiding i the i :labor incidental'.

to the screwing of such :treadsginpositioni with relationto ythes'tread baseior section jc..

lIn assembling theystairway,structura;'

the fiat riser platetgfsecured,to--kthe lower landing, is placed in position asjthel'owermost step I unit is 'mounted between ,the

Vstringers, and the upper landingQ-for thesta1rway 'may be'linpished ofi 1nI any desired` manner above the riser section dof the vupf 1; Theyarious sockets el, and/"are ldravvllfl upf from the sheet, n'n/etalQofV the Astringere, 3a, and' b, thenietal stoelgjbeing pierced ,toformephey Y open top /c'jand the yabutinent'm in; said sock? i etsgf In thisgrnannerithe louter faceof eachiy stringerev and-is yfreefronn'lall projectionsl of any kind .and may thus -{brought flush` a'gain'stithedwall of aibuildingxw1;gy f k The-manner fof Imounting the p Step; units, also permitsl the Stringer-sito]serve;,as-mop boards,gi`yingla finish atthesides of the able of'yariation not Vonlyfvfor Vthe purposefof f Vsecuring'the :desired strength, thereo for resisting yerticalstresses,butthe desired finish Y toVi reeiye. ythe .Various Vstep unitsfand will thus have funiform` strength.fgthroughout every: portion 0f the length. thereot izo tion of Cash unit; imparts; SuiicientiSrengt-h The arrangement lof the col-'operating means,

the sockets e orf, the stirrups g and lz, and the bolts z' and y' at points adjacent-,the forward andthe rear edges of each tread `,section will afford ank effectivel distribution of the weight of a lload upon any treadv section and avoid any likelihood of the tilting kof the step unit; IIence the step units will remain true. since the methods of manufacture permit accuracy in the positioning of these co'- operating members with relation toeach other and to thestringers. 1

The abutment m engaged by the hooked end a upon the head a of the bolt, will pre-v vent any lifting action of rany step unit, the

interlocking of the bolt withits retaining socket forming means upon 4the stringer serving: to firmly position eachl unit with relation to the stringers and to 'the adjoin-v ing units'.` Y y j The abutment m engaging the under face n of the head of the bolt will transmit the Cil terials enterin'gf thereinto.

stresses from all loads upon the tread to the Stringer-s. Y I

All parts of -the istairway structure excepting the bolts z' and may be made of sheet metal which may be readily and accuratelyr fabricated and so formedlas to impart to the stairway the desired rigidity and strength wrhile limiting the weight of the ma- The sheet metal, evenfthough light stoclcbe used, mayby the construction described Vbe effectively used in stairway structures andw-illbe found to possess many advantages as compared with cast metal stairways.

`rIhe use of the spring-coves r not only facilitates the mounting of wear treads g' with relation to thelstep units but also `facilitates the removal of said treads in the-event of=v wear and the necessityV forreplacement. Thel -sprin'giness or flexibility of the cove piece will serve to hold the wear tread Q firm-ly against ythe nosinfg p at all times, it

l'being noted that the construction' of this cove-piece is such that a tongue engages the reafrifedge of the tread Q presented towards t-he riser l aud-that the curved portion there'- of, forming the cove, Vholds said tread Q against the treadv section c.

It is'not my intention to 'limitthe invention to the precise construction and arrangement of parts shown in the drawings, it being apparent that such may be variedV without departing .from the spirit and scope of the invention.

Having described the invention, what I claim as vnew and desire to have protected by Letters Patent, is zy l. A metallic stairway embodying therein metallic stringers, a sequence of step units, each unit'being of sheet metal so formed as togi-ncl'u'de a tread'secti'onand a riser section integral therewith', each tread section hav- Y ing a downwardly presented channel adapt-l ed to span the vedge of the riser section of an adjoiningunit, means adapted to receive,

a bolt, carriedl by and vlocated inwardlyl of said stringers and -upon they lower. face of the tread section of each unit respectively, and bolts engaging said means respectively, whereby said step units are supported from.

said stringers, and said stringere and said' units may be drawn tightly together.

2. A metallic stairway embodying therein metal stringers, a sequence of step units, the material of said'stringers being pierced to form an opening and an abutment below same, strirrups secured to the under side of each of said step units in a position to be adjacent. the openings and abutments and said stringersrespectively, bolts mounted in said stirrups respectively, each of said bolts having a hookedhead and-provided with means adapted to pass through an opening in said stringer and engage below the abut#1 t. In a metallic stairway Vas claimed claim l," a nosing adjacent the channel of each step unit,"a wear tread engageable with said nosing and engageable bythe tread section, and means detachably connected with the riser section in engageable' relati'onwith said wear tread. p

5. In a V metallicV stairway vas claimedv in claim l, a nosing, and channel forming means integrally formed from a strip of sheet metal separate from the metal of the tread and riser, and permanently secured to the edge of the tread section of the unit, al wear tread engageable with said nosing and' engageable bythe tread section, and -m'eans detachably connected with theriser section in engageable relation with said wear tread.

6. In a metallic stairway as claimed in claim l, means supporting" the step units from theystringers and for drawing saidY stringers and said units tightly together,

Vconsisting of a pluralityof rectilineally are ranged socket forming means projecting in wardly Vof each of the stringers, 'the sockets of said means openingupwardly' and Ehaving an abutment formed thereon below n said opening, stirrups' carried upon the under Y side ofthe treadsection of each step unit, and Vbolts mounted in saidl stirrups respectively, each having a head provided with means adapted to pass through the upwardly presented top opening of said sockets and engageable below said abutment, and also engageable with the tread section of the step unit with which it is associated, and nuts carried by said bolts respectively engaging an end of a stirrup.

7. In a metallic stairway as claimed in claim l, socket forming means formed integrally with the material of the stringers by being drawn inwardly to form thesocket with an *upwardly presented opening, and pierced below this opening to form an abutment engageable bya portion ofthe hea'd of a bolt.

provided with an opening therethrough vadjacent the boltl receiving means upon the lower face of Jthe tread section of the unit,

whereby a tool may be engaged with the 1926.V Y s s GEORGE L. BENNETT.

8 Ina metallie stairway as claimed infoy claim l, a stepeunit having a `tread section 

